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Engineering calculators per standards
Pipe sizing, pressure drops, U-value, voltage drops and 40+ other calculations – from sanitary installations to electrical and architecture. Results in seconds, compliant with PN and EN standards.
Calculations per PN, EN, DIN
Results in seconds
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3000+ engineers already use it. No credit card required. See pricing
KalkulatorPro offers convenient
designer tools
Comprehensive calculators for the installation and construction industry. Heating, ventilation, water-sewage, gas, electrical, U coefficient and much more.
Heating
Heating system calculations. Pipe diameter selection, pressure drops, valve authority, expansion vessel, radiator selection, underfloor heating.
Ventilation
Ventilation duct calculations. Diameter selection, air velocity, pressure drops.
Water-Sewage
Water supply and sewage system calculations. Pipe diameter selection, flows, slopes.
Gas
Gas installation calculations. Pipe diameter selection, power to flow conversion, pressure drops.
Architecture
Calculators for architects and designers. U coefficient, media consumption for connection conditions.
Electrical
Electrical installation calculations. Voltage drop in cables, cable sizing per PN-HD 60364-5-52 and N-SEP-E-002 standards.
How it
works?
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Over 40 engineering calculators for various industries.
Get standards-compliant results
Results in seconds, compliant with Polish and European standards PN, EN and DIN.
What our
users say
Join thousands of satisfied engineers who use KalkulatorPro every day.
3000+
Satisfied users
99.9%
Service availability
4
Calculator languages
40+
Calculators
Designing utility networks? Build the longitudinal profile and a CAD-ready DXF.
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1 Month
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49 PLN
for 1 seat for 1 month
40+ engineering calculators
Calculations per PN and EN standards
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Access on any device
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12 Months
one-time payment
+ VAT (23%)
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588 PLN
for 1 seat for 12 months
40+ engineering calculators
Calculations per PN and EN standards
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Frequently asked
questions
Common questions about our calculators for sanitary, gas and electrical engineering
What is KalkulatorPro?
KalkulatorPro is a set of over 40 online engineering calculators for installation designers and contractors. With one tool you can size heating, ventilation, water and sewage, gas and electrical installations, calculate the heat transfer coefficient U and media consumption needed for connection applications.
Who is behind KalkulatorPro?
The service is created by KBM Projekt — a team of sanitary and electrical engineers and developers with many years of design experience. Algorithms are based on current Polish standards and building regulations.
What calculations are available?
Pipe and duct sizing, pressure loss, radiator and underfloor heating selection, expansion vessels, safety valves, heat recovery ventilation, gravity sewerage, low- and medium-pressure gas installations, DHW cylinder sizing, voltage drop and cable sizing, power balance, U-value, interstitial condensation, acoustics and much more.
Are there calculators for the electrical industry?
Yes — KalkulatorPro includes an electrical module: voltage drop, cable cross-section selection (based on current carrying capacity and permissible voltage drop), saveable cable design projects and a power balance calculator for grid connection applications.
How much does access cost?
After registration every new user gets a 5-day free trial with full access to all calculators — no payment details required. After the trial, full access and project saving are available on subscription plans.
How quickly will I receive a response after sending a query?
We try to respond to all inquiries within 1-2 business days. For urgent matters, we encourage you to contact us by phone.
Are there instructions for using the calculators on the site?
Yes, each calculator has built-in tooltips and "How we calculate" modals explaining the methodology. Our Knowledge Base also contains detailed articles and guides with theoretical background and worked examples.
Which standards are the calculations based on?
Algorithms are based on current PN-EN standards (including PN-EN 12831 — heat losses, PN-EN 1717 and PN-92/B-01706 — water supply, PN-EN 12056 — sewerage, PN-HD 60364 — electrical installations) and the Polish Regulation on technical conditions for buildings.
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